Scholarlink

<p>The behavior of nanocomposites based on arabinogalactan with zero-valent Ag (AG-AgNPs) during their thermal decomposition in an inert atmosphere has been studied for the first time, and the kinetic parameters of the processes occurring during this process have been calculated. Samples with different (0.5, 3.5, 16.5%) Ag<sup>0</sup> inorganic nanophase contents and mean nanoparticle size (3.0, 4.2, 17.0&#xa0;nm) were analyzed by simultaneous thermal analysis (STA). The kinetic triplets of the samples were determined by Ozawa–Flynn–Wall (OFW), Kissinger–Akahira–Sunose (KAS), Starink (STK), and Criado methods. The study showed that the presence and average size of nanoparticles have a key influence on the thermal degradation pattern of the nanocomposites. This is confirmed by the occurrence of a decomposition stage preceding the main degradation stage and a decomposition stage in the high temperature region for the nanocomposite with an average nanoparticle size of 17.0&#xa0;nm, compared to the data for the matrix. The nanometal under heating conditions provides more efficient mass loss due to increased thermal conductivity compared to the matrix and the occurrence of chemical processes, particularly polysaccharide dehydration reactions. It was found that the presence of Ag nanoparticles (AgNPs) and an increase in their average size causes a decreased in the thermal stability of the material and a decrease in the average value of the effective activation energy for the nanocomposites degradation stages I, II, and III. A decrease from 344.1 to 175.3&#xa0;kJ&#xa0;mol<sup>−1</sup> (OFW) values of the average effective activation energy was observed for the main stage of thermal degradation of nanocomposites. The dependence of the mean effective activation energy on the conversion degree and the kinetic models showed that the thermal degradation of the AG-AgNPs was a complicated multi-step reaction process. The pre-exponential factor values calculated revealed that the complex chemical reactions occur at the decomposition stages II and III of the samples (3.0, 4.2&#xa0;nm) as well as at the degradation stage III of the sample (17.0&#xa0;nm).</p> Graphical abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

The influence of inorganic Ag0 nanophase on the thermal decomposition of arabinogalactan-based composites: evaluation of kinetic triplets and thermal stability

  • 期刊论文

  • 发表日期：

    2025年4月16日

查看全文
  • Anna V. Zhmurova,
  • Marina V. Zvereva

摘要

The behavior of nanocomposites based on arabinogalactan with zero-valent Ag (AG-AgNPs) during their thermal decomposition in an inert atmosphere has been studied for the first time, and the kinetic parameters of the processes occurring during this process have been calculated. Samples with different (0.5, 3.5, 16.5%) Ag0 inorganic nanophase contents and mean nanoparticle size (3.0, 4.2, 17.0 nm) were analyzed by simultaneous thermal analysis (STA). The kinetic triplets of the samples were determined by Ozawa–Flynn–Wall (OFW), Kissinger–Akahira–Sunose (KAS), Starink (STK), and Criado methods. The study showed that the presence and average size of nanoparticles have a key influence on the thermal degradation pattern of the nanocomposites. This is confirmed by the occurrence of a decomposition stage preceding the main degradation stage and a decomposition stage in the high temperature region for the nanocomposite with an average nanoparticle size of 17.0 nm, compared to the data for the matrix. The nanometal under heating conditions provides more efficient mass loss due to increased thermal conductivity compared to the matrix and the occurrence of chemical processes, particularly polysaccharide dehydration reactions. It was found that the presence of Ag nanoparticles (AgNPs) and an increase in their average size causes a decreased in the thermal stability of the material and a decrease in the average value of the effective activation energy for the nanocomposites degradation stages I, II, and III. A decrease from 344.1 to 175.3 kJ mol−1 (OFW) values of the average effective activation energy was observed for the main stage of thermal degradation of nanocomposites. The dependence of the mean effective activation energy on the conversion degree and the kinetic models showed that the thermal degradation of the AG-AgNPs was a complicated multi-step reaction process. The pre-exponential factor values calculated revealed that the complex chemical reactions occur at the decomposition stages II and III of the samples (3.0, 4.2 nm) as well as at the degradation stage III of the sample (17.0 nm).

Graphical abstract